Agfa Gevaert Nv

Agfa-gevaert

Xeikon N.v.

Marc Herregods

Paul A Delabastita

Dirk K Broddin

Roger Baeten

Koenraad Leontine Van Hulle

Marc Goetschalckx

Eddy Op De Beeck

Geert Noppen

Dirk Tjantele

Peter Somers

In desk top publishing or professional printing, the need exists to print a set of documents which have a generally identical background image and differ from each other by a small area, a page specific image region. A method is described to locate each page specific image region in a background image page layout. A master file stores this background image information along with positional parameters and a file reference to the page specific image region data. The page specific data are stored in one or more data files, generated by a database application program. The master file and page specific file are combined such that the background image is transformed to a bitmap only once, and the page specific data variously modify this bitmap to represent each individual page.

Method for creating multiple documents having identical background

A process is described for digitising the relevant portion of a color image by a system with reduced memory capacity. The color image is scanned twice. The image signals (30) are sub-sampled (I) the first time and spatially reduced (II) the second time to the relevant image portion. The spatial data (35,36) for the relevant image portion are determined on an interactive work station (34), on which the sampled image signals (33) are displayed. Initial sampling and resampling by the scanner take place with the same spatial resolution. By carrying out the sub-sampling and the spatial reduction during scanning, an important saving of memory is realized. Owing to the fact that the color image is digitized in one single step, register faults are avoided.

Interactive color image digitizing system having restricted memory

High quality multilevel halftoning for color images with reduced memory

The generation of personalised documents, or documents including variable data, may require one or more varying overlay images to be printed on top of a background image. In order to avoid the generation of the background image for each document separately, a method is provided to store the background image permanently and to merge it with the overlay images just before printing. A transparency notion may be introduced to avoid masking of the background image by horizontally oriented rectangular overlays. The overlay image and the background image may be generated by a process of multilevel halftoning, suitable for printing by an electrophotographic printing device, using colored toner.

Generation of halftone overlays for combination with halftoned images

A method is described for the rendering of an image on a carrier by a rendering system having a restricted density resolution. A classic screening method for a binary rendering technique is extrapolated to a plurality of energy levels that belong to three classes: non-marking, non-stable and marking stable energy levels. For each class, specific rules must be respected, in order to obtain predictable results without density discontinuities on the carrier. The methods make full use of the spatial and density resolution of the rendering system in areas of high density and increase the reproducibility of low densities by giving up some spatial resolution in the lower density regions.

Screening method for a rendering device having restricted density

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Hever, Belgium

Marc Herregods